tree 3be4cdc338bf004f7b8c6c70baf7fb78ad252844
parent 2584e517320bd48dc8d20e38a2621a2dbe58fade
author Johannes Weiner <hannes@cmpxchg.org> 1238538192 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1238601553 -0700

mm: move pagevec stripping to save unlock-relock

In shrink_active_list() after the deactivation loop, we strip buffer heads
from the potentially remaining pages in the pagevec.

Currently, this drops the zone's lru lock for stripping, only to reacquire
it again afterwards to update statistics.

It is not necessary to strip the pages before updating the stats, so move
the whole thing out of the protected region and save the extra locking.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: MinChan Kim <minchan.kim@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>